Effect of hypothyroidism on the hypothalamic-pituitary-ovarian axis and reproductive function of pregnant rats.
Jianran Sun, Cancan Hui, Tongjia Xia, Min Xu, Datong Deng, Faming Pan, Youmin Wang
Author Information
Jianran Sun: Department of Endocrinology, Institute of Endocrinology and Metabolism, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, 230022, Anhui, China.
Cancan Hui: Department of Endocrinology, Institute of Endocrinology and Metabolism, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, 230022, Anhui, China.
Tongjia Xia: Department of Endocrinology, Institute of Endocrinology and Metabolism, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, 230022, Anhui, China.
Min Xu: Department of Endocrinology, Institute of Endocrinology and Metabolism, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, 230022, Anhui, China.
Datong Deng: Department of Endocrinology, Institute of Endocrinology and Metabolism, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, 230022, Anhui, China. dengdayong@ahmu.edu.cn. ORCID
Faming Pan: Department of Epidemiology and Biostatistics,School of Public Health, Anhui Medical University,81Meishan Road, Hefei, 230032, Anhui, China.
Youmin Wang: Department of Endocrinology, Institute of Endocrinology and Metabolism, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, 230022, Anhui, China.
BACKGROUND: This study aimed to detect changes in hormone levels in the hypothalamic-pituitary-ovarian axis in Sprague-Dawley (SD) rats with hypothyroidism, and identify differences in the pregnancy and abortion rates of female adult rats. The potential role of gonadotropin releasing hormone (GnRH) as the link between the hypothalamic-pituitary-ovarian axis and reproductive function regulated by thyroid hormones was also investigated. METHODS: Female SD rats (n = 136) were causally classified into two groups: the normal-drinking-water group (n = 60) and the 0.05% propylthiouracil-drinking-water group (PTU 2 mg/kg/day, n = 76) to establish an adult rat model of hypothyroidism (6 weeks). Female and male rats at a ratio of 1:2 were used to establish a hypothyroidism pregnancy model. GnRH mRNA and GnRH receptor (GnRHR) expression in rats was detected using real time quantitative PCR(qRT-PCR) and immunohistochemistry, respectively. RESULTS: The abortion rate differed significantly between the hypothyroidism pregnancy group and the normal pregnancy group (P < 0.05). No significant differences were found in the distribution of the GnRHR among the five nuclei (hypothalamic arcuate nucleus, hypothalamic ventromedial nucleus, hypothalamic anterior nucleus, paraventricular nucleus of the hypothalamus, and ventral premammillary nucleus) of the hypothalamus and ovary (P > 0.05). Hypothyroidism had no significant effect on GnRH mRNA expression in the hypothalamic-pituitary-ovarian axis in the four groups (normal control group, normal pregnancy group, hypothyroidism pregnancy group, and hypothyroidism group) (P > 0.05). CONCLUSIONS: Hypothyroidism had an adverse impact on pregnancy in rats and may affect the distribution of pituitary GnRHR, whereas it did not obviously affect the distribution of GnRHR in the nuclei of the hypothalamus and ovary. Hypothyroidism had no effect on GnRH mRNA expression.
